
Robotic End-of-Arm Tooling
Trends in key markets
By:
John Westbeld Engineering Manager SAS Automation, LLC.
www.sasgripper.com
Robotic sales have
increased over recent years in the non-automotive
markets as the cost of robots goes down and familiarity
of robotic cells increases. North American companies can
readily justify ROI when they look at competition,
quality, productivity, and flexibility issues.
Packaging, palletizing, and other material handling
applications are key areas where robotic cells have
assisted the non-automotive markets.
As the growth of robotic
sales has increased in the non-automotive markets so has
the need for End-of-Arm Tooling (EOAT) or end effector
to handle a wide variety of product and work pieces.
Since a robot is only as good as it’s EOAT in any market
or application, the requirements that the eoat secure
and manipulate the product without damaging it is
critical to the success of the cell.
Injection Molding
EOAT for the plastic injection molding industry need to
be flexible. Several factors of the molding process and
part affect the type of eoat needed:
- Parts that stick or
need to be manipulated to get them off of the mold
- Avoiding damage to
Class A surfaces
- Difficult applications
including insert molding and over-molding
- Multiple cavities
- Additional operations
including degating, assembly, or packing
All of these factors can
dictate whether you use standard eoat with off-the-shelf
components such as vacuum cups and sprue pliers or a
custom eoat with grippers and actuators to remove the
parts form the mold. Innovations in EOAT have also
included programmable EOAT that can be used with several
molded parts. As the part features change from mold to
mold the programmable actuators on the EOAT can be
manipulated by the robot controller to adjust part
gripping mechanisms to the desired position.
Other difficult
applications in the plastic injection molding industry
that require unique eoat to support feasibility of using
a robot are insert molding applications. These
applications may require several inserts to be placed
into the mold so that plastic can be molded around them
to form a part. A typical application of this is
inserting metallic threaded studs or bushings to
facilitate the assembly of the plastic part. The EOAT
would have to secure the inserts as well as remove the
molded parts from the mold. The EOAT may need to locate
onto the mold for accuracy and have alignment
compensators to overcome insert tolerance issues.
Part, actuator position,
and eoat sensing are critical in difficult injection
molding applications. There can be several eoat for
various molds that are run in any given injection
molding machine. This creates a need for the robot to
identify which EOAT it has. This can be accommodated
through creative wiring or RFID. Part and actuator
position sensing is also critical especially when the
parts are die-locked to some degree. The EOAT may need
to go through a progression of part manipulating motions
to get the part off of the mold made possible by several
actuators working in succession. Any deviation from this
progression could lead to crashes or damaged parts. Part
and actuator sensing make it possible for the robot to
know which part of the progression it is at any time.
Multi-cavitation adds to the complexity and increases
the need for sensing.
Packaging &
Palletizing
Palletizing applications have brought robots to various
markets. Palletizing heavy cases or high speed
palletizing may require robots. Case palletizing can
require different types of EOAT depending on the quality
of the corrugated material, the number of cases to
manipulate to keep up with throughput, and the product
in the cases. EOAT with grippers to secure the outside
of the case can be used when the product inside the case
can maintain the cases shape when it is gripped. This
type of EOAT works well with heavy, sturdy cases.
Individual grippers also allow the possibility of
placing cases independently for various configurations.
Large bag palletizing can
be accommodated with EOAT with forks to grip the bag
underneath through a roller conveyor. Tines on the EOAT
reach in between the rollers to firmly grasp the bag
irrespective of content. This enables the robot to
firmly manipulate the bag and palletize it at high
speeds.
Large vacuum plates can
also be used for securing various sized and contoured
product. It consists of a foam rubber pad with an array
of holes for vacuum valves. The vacuum is drawn through
the valves to secure the product. The valves that do not
make contact with the product automatically close so you
do not lose vacuum. Vacuum plates can be used to
palletize entire layers of product or individual units.
They can also be zoned to palletize units individually.
The type of products the vacuum plates are good for
include: cases, bags, cans, and various other products.
Robots are a good fit
where ever consistency, reliability, productivity,
flexibility, and cost issues are present. Many North
American companies in various markets utilize robots and
their EOAT to be more competitive on a global scale.
About SAS Automation
SAS is a leading
supplier of modular EOAT components and robotic
gripper systems – capable of servicing any part and
any robot. SAS manufactures in the U.S. “get a
grip!”, and distributes “nip it!” Nile sprue
nipper line, and “GRIP IT!“ Asian chucking/gripper
line. SAS is ISO 9001:2000 Quality Certified and
specialists in robotic end-of-arm tooling &
gripper systems, sprue nippers, CNC degating &
Insert Mold tooling for manufacturing, packaging &
plastics industries.
SAS Automation Robotergreifsysteme
GmbH - Europe
Im Schlehert 26
D-76187 Karlsruhe, Germany
Tel: +49 (0)721 26306 - 0
Email:
info@sas-automation.com
Web:
www.sas-automation.com
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